"I think for schools there should be no question about it being done for free, given that the safety of our students is paramount."

Ms Callister says by the time she checks contractors, new staff and any parent help she'll be facing a big bill.

"Suddenly my budget that might've been looking okay has got a minimum chunk of $500 chopped out of it."

The Policing (Cost Recovery) Amendment Act 2016 was passed by Parliament in November. It will allow police to charge $8.50 plus GST per vetting request.

The fees are in response to a higher demand for police checks in an attempt cover costs and adhere to the 20-day turnaround.

Police expect to spend $3.7 million in the 2016/17 financial year to cover staff, infrastructure, banking and training for the service.

There are exemptions from the charges for charities, or organisations that apply for fewer than 20 per year.

There is also a waiver if an agency is facing extreme financial hardship, or in the case of extreme circumstances such as natural disasters or national security emergencies.

However a Cabinet paper on the changes outlines these waivers will be at the Commissioner's discretion and police expect them to be needed "relatively rarely".

But Ms Callister says if schools are forced to pay, the money will have to come from an already stretched operational budget and it will be the children who miss out on resources.

"We're a Government-funded organisation - I mean, who's paying who here, this is a crazy kind of money-go-round."

The Cabinet paper says some of the vetting will still be covered by police - therefore Government-funded - for things such as police recruitment and national security purposes, including the British and Irish Lions Tour.

The number of checks needing police funding was forecast to be 28,268 in 2016/17.

At $8.50 (GST exclusive) per vetting request, the total cost would be $240,278 (GST exclusive).

An email sent to schools by police says the changes have already been signalled, however Ms Callister says she's been given no guidance from the Ministry of Education on it.